You will see an F6, but as I have mentioned before, I am
bifurcating the offerings from FW. I will probably make only 10
of the F6 and then publish the schematic. Non "F" series are
slated for continuous production, and there will not be a DIY
version until production is terminated.

excellent!! i can feel a GB for the R100A coming on, have you tested these parts Nelson? X? unfortunately anything that wont accept balanced inputs is kinda out for me except for novelty reasons as my main rig only has balanced outs